1. Field of the Invention
The present invention relates to piping structure preferably used for connecting external pipes to a heat exchanger such as a condenser in a refrigeration system for car air-conditioners. It also relates to a piping joint block for a heat exchanger and a heat exchanger equipped with the joint block.
2. Description of Related Art
Japanese Patent Unexamined Laid-open Publication No. 4-306492 discloses a condenser for use in a refrigeration system for car air-conditioners. This condenser includes a pair of headers and a plurality of heat exchanging tubes disposed between the pair of headers with their opposite ends connected to the headers. The headers are provided with partitions to divide the plurality of heat exchanging tubes into a plurality of passes, whereby the refrigerant introduced into one of the headers through the refrigerant inlet port formed in the header flows through each pass in order, and is flowed out of the condenser through the refrigerant outlet port formed in the header.
In this condenser, a flange connection system using a joint block is employed for connecting the refrigerant inlet and outlet pipes, which are connected to the refrigerant inlet port and the refrigerant outlet port of the condenser body, respectively, to external pipes connected to a compressor, an expansion valve, etc. In detail, a single joint block is attached to the ends of the refrigerant inlet and outlet pipes, and an external piping flange member is attached to each end of the external pipes. Each external piping flange member is connected to the joint block with a screw in the state that the flange member is fitted on the flange face of the joint block, whereby the refrigerant inlet pipe and the refrigerant outlet pipe are connected to the first and second external pipes through the first and second communication passages formed in the joint block, respectively.
In this joint block, both openings of the communication passages, which is in fluid communication with the refrigerant inlet and outlet pipes, are formed on the same flange face so as to connect the first and second external pipes to the joint block from the same direction.
By the way, depending on a type of a car, it is sometimes required to connect the first and second external pipes to the joint block from different directions. In this case, there are the following problems. That is, it is required to form two flange faces facing toward different directions on the joint block, an opening of a first communication passage on one of the flange faces and an opening of a second communication passage on another flange face. However, in this case, different faces of the joint block constitutes flange faces and the communication passages to be formed in the joint block is complicated in shape, which increases difficulties in forming the joint block and the manufacturing cost.
An object of the present invention is to provide piping structure for a heat exchanger, which enables refrigerant inlet and outlet external pipes to be connected from different directions and can reduce the manufacturing cost.
Another object of the present invention is to provide a joint block for a heat exchanger, which is suitably used for the aforementioned piping structure.
Still another object of the present invention is to provide a heat exchanger equipped with the aforementioned joint block.
According to a first aspect of the present invention, a piping structure for a heat exchanger includes a refrigerant inlet pipe to be connected to the heat exchanger, a first joint block connected to an end of the refrigerant inlet pipe, a refrigerant outlet pipe to be connected to the heat exchanger, a second joint block connected to an end of the refrigerant outlet pipe, a first external pipe, a first flange member connected to an end of the first external pipe for connecting the first external pipe to the first joint block, a second external pipe, and a second flange member connected to an end of the second external pipe for connecting the second external pipe to the second joint block. The first joint block has a first engaging portion and a first flange face for connecting the first flange member, and the second joint block has a second engaging portion corresponding to the first engaging portion and a second flange face for connecting the second flange member. The first and second joint blocks are connected with each other in a state where the first engaging portion is engaged with the second engaging portion, and a facing direction of the first flange face is different from that of the second flange face in a state where the first joint block and the second joint block are connected each other. Thus, the first external pipe and the second external pipe are connected to the first joint block and the second joint block, respectively, from different directions.
In this piping structure, since the facing direction of the second flange face of the second joint block is different from that of the first flange face of the first joint block, it is possible to connect the flange member of the first external pipe and that of the second external pipe to the first flange face and the second flange face, respectively, from different directions with no difficulty. Furthermore, both the joint blocks can be positioned by simply engaging the first engaging portion of the first joint block with the second engaging portion of the second joint block, which enables an easy connection of the joint blocks.
It is preferable that one of the first engaging portion and the second engaging portion is an engaging dented portion and the other thereof is an engaging member to be engaged with the engaging dented portion, and wherein the first joint block and the second joint block are connected each other in a positioned manner with the engaging member engaged with the engaging dented portion. In this case, both the joint blocks can be positioned easily.
According to a second aspect of the present invention, a joint block for a heat exchanger includes a first joint block to be connected to an end of a refrigerant inlet pipe connected to the heat exchanger and a second joint block to be connected to an end of a refrigerant outlet pipe connected to the heat exchanger. The first joint block has a first engaging portion and a first flange face for connecting a first flange member connected to a first external pipe, the second joint block has a second engaging portion corresponding to the first engaging portion and a second flange face for connecting a second flange member connected to a second external pipe. The first and second joint blocks are connected each other in a state where the first engaging portion is engaged with the second engaging portion, and a facing direction of the first flange face is different from that of the second flange face when the first joint block and the second joint block are connected each other. Thus, the first external pipe and the second external pipe are connected to the first joint block and the second joint block, respectively, from different directions.
In this joint block, it is possible to separately manufacture the first and second joint blocks each having a single flange face and a single communication passage. Accordingly, it is easy to manufacture the joint blocks as compared with manufacturing a single joint block having two flange faces and two communication passages, resulting in a reduced manufacturing cost.
According to a third aspect of the present invention, a heat exchanger with a piping joint block includes a heat exchanger body, a refrigerant inlet pipe with one end communicated with the heat exchanger for introducing refrigerant into the heat exchanger, a refrigerant outlet pipe with one end communicated with the heat exchanger for discharging refrigerant from the heat exchanger, a first joint block connected to the other end of the refrigerant inlet pipe, and a second joint block connected to the other end of the refrigerant outlet pipe. The first joint block has a first engaging portion and a first flange face for connecting a first flange member connected to a first external pipe, the second joint block has a second engaging portion corresponding to the first engaging portion and a second flange face for connecting a second flange member connected to a second external pipe, and the first and second joint blocks are connected with each other in a state where the first engaging portion is engaged with the second engaging portion. The facing direction of the first flange face is different from that of the second flange face when the first joint block and the second joint block are connected each other, whereby the first external pipe and the second external pipe are connected to the first joint block and the second joint block, respectively, from different directions.
In this heat exchanger, since the facing direction of the second flange face of the second joint block is different from that of the first flange face of the first joint block, it is possible to connect the flange member of the first external pipe and that of the second external pipe to the first flange face and the second flange face, respectively, from different directions with no difficulty.